Recently, various terminals and networks have been used according to establishment of a multimedia environment, and in line with this, user needs have also been diversified.
For example, as terminal performance and computing ability are diversified, a variety of performance is supported by devices. Also, networks via which information is transmitted have also been diversified in functions such as forms of transmitted information, amounts and speeds of information, and the like, as well as external structures such as wired/wireless networks. Users may select a terminal and a network to be used according to a desired function, and a variety of spectrums of terminals and networks are provided to users by enterprises.
In this connection, recently, a broadcast having high definition resolution has been expansively provided worldwide, as well as domestically, a great number of users are becoming accustomed to high resolution, high picture images. Thus, a great many image service-related organizations or institutions have applied the spur to develop a next-generation image display device.
Also, in addition to HDTV, as interests in ultra-high definition (UHD) having resolution equal to or greater than 4 times the HDTV are increasing, demand for a technique of compressing and processing an image having high resolution and high picture quality is on the rise.
In order to compress and process an image, inter-prediction technique for predicting a pixel value included in a current picture from a temporally previous and/or subsequent picture, an intra-prediction technique for predicting a different pixel value included in a current picture by using pixel information within the current picture, and an entropy encoding technique for allocating a short code to a symbol having high frequency and a long code to a symbol having low frequency, or the like, may be used.
As mentioned above, in consideration of the terminals and networks each supporting different functions and diversified user needs, quality, size, frame, and the like, of supported images, are required to be diversified.
Thus, due to heterogeneous communication networks and various types of terminals having various functions, scalability variably supporting picture quality, resolution, size, frame rate, and the like, is an important function of video formatting.
Thus, in order to provide services required by users in various environments based on a high efficiency video encoding method, it is required to provide a scalability function allowing for effective video encoding and decoding in terms of time, space, picture quality, and the like.